Safety helmet



Nov 7, 1967 D. D. WEBB 3,350,718

SAFETY HELMET Filed Feb. 10, 1966 INVENTOR DANIEL D. WEBB BY 6% final (Qua ATTORNEYS United States Patent 3,350,718 SAFETY HELMET Daniel D. Webb, Birmingham, Mich., assignor to American Safety Equipment Corporation of Michigan, Southfield, Mich.

Filed Feb.-10, 1966, Ser. No. 526,510 4 Claims. (Cl. 2--3) This invention relates to an improved lightweight safety helmet construction.

The ideal safety helmet provides a maximum of protection to the head of the wearer while being sufiiciently light in weight to prevent fatigue when worn for extended periods of time. This is especially true when the helmet is intended to be worn by policemen, who cruise continuously on motorcycles or in patrol cars for many hours.

Accordingly, it is an object of this invention to provide an improved safety helmet which combines a maximum of impact protection for the head of the wearer while remaining light in weight.

This and other objects and advantages of this invention will become apparent from the following specification when considered in conjunction with the accompanying drawings.

In these drawings:

FIG. 1 is a cross-sectional elevation through the safety helmet of this invention;

FIG. 2 is a perspective view of the helmet of FIG. 1;

FIG. 3 is an enlarged cross-sectional view taken in the direction of arrows 33 of FIG. 1, showing the chin strap and rank strip secured to the helmet.

Referring now to FIG. 1 of the drawings, safety helmet 10 generally comprises an outer shell 12, an inner shell 14 spaced from outer shell 12, a relatively thick resilient liner 16 and a stiff reinforcing shell 18.

The outer and inner shells 12 and 14, respectively, are fabricated of a relatively stiff, semi-flexible sheet material which flexes under pressure, as for example, of about 5 to lbs. applied with the ball of the thumb, and which immediately returns to its former shape on release of that pressure. One suitable material, having these properties, is acrilonitrile butadiene styrene (commonly known as ABS), which is a thermal-forming plastic, formed as a sheet of approximately .05 to .06 inch in thickness.

Outer shell 12 is formed with an outwardly offset embossment or ridge 13 across its upper front portion and an offset or outwardly ridged lower edge 13a.

The intermediate resilient liner 16 is preferably formed of a foamed plastic material such as polystyrene. Such a material is characterized by being resilient and compressible under pressure, while having a relatively slow recovery rate in returning to its former shape upon release of pressure.

Between resilient liner 16 and outer shell 12 lies an extremely hard and stiff reinforcing shell 18. Shell 18 may be formed of a material such as glass fiber and a suitable resin having a thickness of approximately .125 inch.

The three shells and the liner are sized to fit closely together, one inside the other as shown. However, inner layer 14 is slightly oversize so that it squeezes the liner 16, to cause it to compress slightly, and thus in turn squeeze the protective shell 18 against the other shell. Hence, these parts are squeezed or clamped together to frictionally hold the liner 16 and protective shell 18 in place. The inner and outer shells are positively fastened together by a resilient edge bead 20 which clamps over and is adhesively secured to the entire periphery of outer shell 12 and inner shell 14. Additional fastening is provided by a pair of rivets 22, one of these rivets appearing approximately'midway on each side of the helmet (only one being visible in the drawings).

3,350,718 Patented Nov. 7, 1967 A plurality of female snap fasteners 24 are provided on the interior surface of inner shell 14 to receive a head cradling structure. A suitable cradling structure is disclosed in a co-pending application of the common assignee, Ser. No. 422,120, filed Dec. 30, 1964.

Male snap fasteners 26, secured to the inner shell 14, are provided for snap fastening various helmet accessories, such as a rain flap adapted to hang from the rear interior of the helmet down the back of the wearer to prevent rain water from running inside of the collar.

A male snap fastener 28 is secured to inner shell 14 on each side of helmet 10 for anchoring chin strap 32.

Referring now to FIGS. 2 and 3, a rank strip 30 is secured to the lower front portion of the helmet for identifying the rank of the individual wearing it. An opening 31 in rank strip 30 is slipped over an exterior male snap fastener 34 which forms the outer portion of rivet 22. Chin strap 32 is provided with a pair of female snap fasteners 36 and 38 at each end for securing to fasteners 28 and 34, respectively. The double fastening arrangement for the chin strap insures that the helmet will not easily be knocked from the wearers head. Thus, rivet 22 performs the dual function of securing together the inner and outer shell of the helmet while also providing an anchoring point for a removable rank strip and a removable chin strap.

It will be observed that the relatively heavy reinforcing shell 18 does not extend down to the extreme lower periphery of helmet 10. This configuration effects a substantial saving in weight, without any significant loss in protection. In addition, it permits the reinforcing shell to move relative to the inner end outer shells, upon impact. By thus relying upon an inner liner to provide substantially all of the penetration resistance, the outer liner, having greater area, can be made of a lighter weight abrasion resistant material.

The outer shell ridges 13 and 13a, plus the limited positive securing means for the outer and inner shells, i.e., rivets 22 and edge bead 20, permit the three shells and liner to float relative to one another and to flex and displace readily under impact, thereby individually and jointly absorbing impact forces. Reinforcing shell 18 and resilient liner 16 are entirely free of any anchoring means, and are thus afforded the maximum freedom of movement. Further the outer shell ridges permit relative sliding movement of the outer shell in response to dragging or abrasive type forces to thereby absorb such forces, the ridges thereby, in effect, acting like springs.

The safety helmet of this invention also permits ready disassembly for replacement of components. Edge bead may be removed off of the rims of outer shell 12 and inner liner 14, and the removal of rivets 22 then permits complete disassembly of the helmet.

This invention may be further developed within the scope of the following claims. Accordingly, the above specification is to be interpreted as merely illustrative of a single embodiment, rather than in a strictly limited sense.

I now claim:

1. A safety helmet comprising:

a thin lightweight, semi-flexible,

pherical, outer shell;

a thin lightweight, semi-flexible inner shell, substantially concentric with said outer shell;

a resiliently compressible, shock absorbing liner sandwiched between said inner shell and outer shell;

a stiif reinforcing shell sandwiched between said outer shell and said shock absorbing liner;

means securing said outer shell and said inner shell together adjacent their lower rims and being otherwise free to float relative to each other;

said shock absorber liner and said reinforcing shell substantially hemisbeing free of positive securement and being frictionally clamped in place.

2. The safety helmet of claim 1, wherein the said outer shell and said inner shell are secured together by means of a pair of rivets, the outer head of each of said rivets being adapted to form an anchoring means for a rankidentifying strip and a chin strap.

3. The safety helmet of claim 1, and wherein said outer shell, liner and reinforcing shell are of a size to closely fit one within the other, and said inner shell being slightly oversize to thereby compress the liner and tightly clamp the reinforcing shell in place.

4. The safety helmet of claim 1, and an outwardly embossed ridge formed in the outer shell, thereby providing for deflective movement of the outer shell material in response to abrasion type forces applied to said outer shell in its surface direction.

References Cited UNITED STATES PATENTS JORDAN FRANKLIN, Primary Examiner.

J. R. BOLER, Assistant Examiner. 

1. A SAFETY HELMET COMPRISING: A THIN LIGHTWEIGHT, SEMI-FLEXIBLE, SUBSTANTIALLY HEMISPHERICAL, OUTER SHELL; A THIN LIGHTWEIGHT, SEMI-FLEXIBLE INNER SHELL, SUBSTANTIALLY CONCENTRIC WITH SAID OUTER SHELL; A RESILIENTLY COMPRESSIBLE, SHOCK ABSORBING LINER SANDWICHED BETWEEN SAID INNER SHELL OUTER SHELL; A STIFF REINFORCING SHELL SANDWICHED BETWEEN SAID OUTER SHELL AND SHOCK ABSORBING LINER; MEANS SECURING SAID OUTER SHELL AND SAID INNER SHELL TOGETHER ADJACENT THEIR LOWER RIMS AND BEING OTHERWISE FREE TO FLOAT RELATIVE TO EACH OTHER; SAID SHOCK ABSORBER LINER AND SAID REINFORCING SHELL BEING FREE OF POSITIVE SECUREMENT AND BEING FRICTIONALLY CLAMPED IN PLACE. 